Objective: To investigate the effect of Porphyromonas gingivalis (Pg) with different fimA genotypes on vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) production by human umbilical vein endothelial cells (HUVEC).
Methods: In the present study, PgATCC33277 (type I fimA genotype), WCSP 115 (type II fimA genotype), W83 (type IV fimA genotype), and Escherichia coli-lipopolysaccharide (Ec-LPS) were designed as experimental group 1, 2, 3, and positive control group, respectively, to stimulate HUVEC, and the un-stimulated HUVEC were analyzed as negative control group. The three strains of Pg were cultured anaerobically in standard condition, and then the Pg cells and Ec-LPS were co-cultured with HUVEC for 2, 6, and 24 h, respectively. The amount of ICAM-1 and VCAM-1 produced by HUVEC was detected with flow cytometry (FCM). The expression of ICAM-1 and VCAM-1 by HUVEC were assayed with confocal laser scanning microscope (CLSM).
Results: The expression of ICAM-1 on the surface of HUVEC were intensified after infected by Pg with I, II, and IV fimA genotypes (P < 0.05). The amounts of ICAM-1 were 60.27 ± 5.43, 80.81 ± 1.44, and 85.94 ± 2.56 for Pg with type I fimA genotype, 86.69 ± 8.81, 90.19 ± 0.00, and 96.18 ± 0.48 for Pg with type II fimA genotype, 59.66 ± 0.40, 85.79 ± 4.86, and 96.04 ± 2.07 for Pg with type IV fimA genotype at 2, 6 and 24 h after infection, respectively. The up-regulation effects caused by Pg with type II and IV fimA genotypes were stronger than those caused by Pg with type I fimA genotype at different time points except at 2 h (P < 0.05). Under the present experimental condition, infected by Pg with type I, II and IV fimA genotypes stimulated low expression of VCAM-1 by HUVEC, it showed no significant differences among all the groups (P > 0.05). Expression of ICAM-1 and VCAM-1 in Pg infected HUVEC were confirmed by CLSM. Infection of HUVEC with Pg resulted in more fluorescence staining of ICAM-1 and VCAM-1 compared with that in uninfected HUVEC cultures.
Conclusions: The virulence and pathogenicity of Pg is associated with its fimA genotypes, Pg with type II and IV fimA genes possess stronger ability to stimulate HUVEC to up-regulate the expression of cell adhesion molecules, which may lead to disorders in vascular endothelial function.